Building block for construction toy set



FIG. 1 is an isometric view from above of a building block for construction toy set in accordance with the new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a back elevational view thereof;

FIG. 4 is a side elevational view of a first side thereof,;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a side elevational view of a second side thereof.

The bottom features thereof form no part of the claimed design. 

CLAIM The ornamental design for a building block for construction toy set, as shown and described. 